Upper Limb Flashcards
The space directly underneath the GH Joint
Axilla
Created by Skin and Axillary Fascia.
-Fascia attaches in front to the Pectoralis Major m. to form the Anterior Axillary Fold
-Fascia attaches posteriorly to the Latissimus Dorsi m. and Teres Major m. to form the Posterior Axillary fold
-Fascia envelopes these and is drawn tight, causing an infold of the fascia called the hollow of the armpit
Axillary Floor
Triangular Shaped.
-Formed by the Clavicle (in front), scapula (behind), and 1st rib (medially)
-A portal to the axilla if you were to enter from a superior direction
Apex of the Axilla
Anterior: Anterior Axillary Fold (Pectoralis Major m.)
Posterior: Posterior Axillary Fold (Latissismus Dorsi m. and Teres Major m.)
Medially: Upper portion of the Serratus Anterior m.
Borders of the Axilla
-Fat (packing of space -bubble wrap)
-Fascia
-Axillary lymph nodes
-Axillary Artery
-Brachial Plexus
Contents of the Axilla
Fascia that forms the floor of the Axilla and runs from the Pectoralis Major m. in front to the Teres Major m. and Latissimus Dorsi m. behind.
-Makes the hollow of the armpit that exists between the Anterior and Posterior Axillary Folds
-Stretching pulls it inward by being taut
Axillary Fascia
Fascia wrapped around the Axillary Artery & Veins and Brachial Plexus to hold them together.
-Derived from scalene and pre-vertebral fascia
-Forms a “Fascial Tube”
-Axillary vein exits distally to run by itself
Axillary Sheath
Deep to the Axillary Fascia. Covers the Axilla Anteriorly.
-Fascia that is stretched between the Subclavius m. and the Pectoralis Minor m.
-An opaque window that looks into the Axilla
-Ends in the Suspensory ligament of the Axilla (Gerdy’s).
Clavipectoral Fascia
A ligament that runs from the Clavipectoral Fascia and attaches it into the Axillary Fascia.
-Wrinkles up, enhancing the “hollow” of the armpit. Accentuates the borders
Suspensory Ligament of the Axilla (Gerdy’s)
Structures going from the axilla to the outside (and vice versa) have to pierce this.
- “Window” into the Axilla
Clavipectoral Fascia
-Cephalic Vein: enters Axilla to drain into the Axillary Vein
-Thoracoacromial Artery (& Vein): exits Axilla to supply Pectoralis Major/Minor, Deltoid, and Subclavius muscles.
-Lateral Pectoral nerve: exits axilla to get to the Pectoralis Major m. to innervate it.
Structures passing through the Clavipectoral Fascia
Longest vein in the upper limb. Starts dorsally on the hand, runs up forearm, all the way to upper arm, where it makes a U-turn in between Pectoralis Major m. and Deltoid m. (called the Delto-pectoral groove), pierces the Clavipectoral Fascia, and drains into the Axillary Vein
Cephalic Vein
A branch off of the Axillary Artery that supplies the Pectoralis Major/Minor m., Deltoid m., and Subclavius m.
Thoracoacromial Artery
Comes off of the Lateral Cord of the Brachial Plexus, passes over Pectoralis Minor m., pierces the Clavipectoral Fascia, and innervates Pectoralis Major m.
Lateral Pectoral Nerve
Refers to the GH Joint (proximal humerus) down to the elbow
Brachium (Arm)
Refers to the elbow joint to the wrist
Antebrachium (forearm)
What are the components of the flexor compartment of the Arm?
-Biceps Brachii (long and short heads) m.
-Brachialis m.
-Coracobrachialis m.
A large muscle with 2 heads: short (medial) and long (lateral)
-Elbow flexor
-Supinates the forearm
-Long head also flexes the GH joint
-Innervated by the Musculocutaneous Nerve
Biceps Brachii muscle
Forms a tendon that approaches the GH Joint, burrows into the capsule, and attaches to the Supraglenoid Tubercle on the rim of the Glenoid Fossa
-Flexes the GH joint
Lateral (long) Head of the Biceps Brachii Muscle
Attaches to the Coracoid Process of the Scapula
Short Head of the Biceps Brachii Muscle
Best elbow flexor muscle
-Origin: Humerus
Crosses elbow joint anteriorly
-Inserts into Forearm
-Innervated by the Musculocutaneous Nerve
Brachialis Muscle
Muscle that flexes and adducts the GH joint.
-Origin: Coracoid Process of the Scapula
-Insertion: Brachialis m.
-Innervated by the Musculocutaneous Nerve
Coracobrachialis Muscle
Fascia that extends down from the shoulder and wraps around muscles of the flexor compartment to keep them intact (investing fascia)
Brachial Fascia
Muscle that has 3 heads that all extend the elbow when they contract (straightens elbow out)
-Insert into the Olecranon Process
-Innervated by the Radial Nerve
Triceps Brachii Muscle
-Elbow Extender
-Also extends the GH Joint (brings it back down to starting position)
-Origin: Infraglenoid Tubercle (bottom of glenoid fossa)
Long Head of the Triceps Brachii
-Elbow Extender
-Origin: posterior portion of the humerus
Lateral Head of the Triceps Brachii
-Elbow Extender
-Origin: posterior portion of the humerus
-Have to cut and reflect Lateral Head to view
Short Head (medial head) of the Triceps Brachii
Nerve that innervates the Flexor Compartment of the Arm.
-Has to be anesthetized by itself- lies outside of the Axillary Sheath.
-Inject into the Coracobrachialis Muscle
-Innervates Biceps Brachii m., Brachialis m., and Coracobrachialis m.
Musculocutaneous Nerve
Nerve that innervates the Extensor compartment of the arm
-Triceps Brachii muscle
Radial Nerve
An interruption of muscle between the Biceps Brachii m. and the Triceps Brachii muscle.
-Filled in with fibrous, fatty tissue
-Can feel an indent between muscles.
-Contains several structures
Medial Intermuscular Septum
An interruption between the Brachialis m. and the Triceps Brachii m.
-Very small, not really a gap
Lateral Intermuscular Septum
List the structures contained in the Medial Intermuscular Septum (7)
-Ulnar Nerve
-Median Nerve
-Brachial Artery
-Lateral/Medial brachial Veins (on either side of Brachial Artery)
-Medial Antebrachial Cutaneous Nerve (sensory to medial forearm)
-Basilic Vein (largest vein in upper limb)
What structure runs with the Median Nerve?
Brachial Artery
What structure runs with the Basilic Vein?
Medial Antebrachial Cutaneous Nerve
In the proximal portion of the arm, brachial artery is _____ and the median nerve is ______.
Medial; lateral
As they move distally, the brachial artery and median nerve cross, and the brachial artery is now ______ and the median nerve is now ______.
Lateral; Medial
This nerve splits off from the others to curve around the posterior elbow.
Ulnar Nerve
Nerve that supplies sensory and motor function to the muscles in the anterior compartment of the forearm, and the muscles on the thumb side of your hand.
Median Nerve
How do you anesthetize the Musculocutaneous Nerve?
Inject the Coracobrachialis Muscle.
Occurs when the Musculocutaneous nerve runs out of branches and continues as a sensory branch that runs down the forearm.
-Provides sensory to the lateral aspect of the forearm
Lateral Antebrachial Cutaneous Nerve
Anesthesia to the Musculocutaneous Nerve should cause what?
Inability to flex the elbow, and loss of sensation to the lateral forearm.
Nerve that comes off of the brachial plexus and runs posteriorly along the humerus.
-Innervates the Triceps Brachii m.
-Has a Posterior Cutaneous branch that provides sensation to the posterior arm (skin covering Triceps Brachii m).
Radial Nerve
Nerve that supplies sensation to the posterior arm (skin covering Triceps Brachii m.)
Posterior Cutaneous branch of the Radial Nerve
Branch off of the medial cord of the Brachial Plexus that supplies sensation to the medial aspect of the arm.
Medial Brachial Cutaneous Nerve
Branch off of the medial cord of the Brachial Plexus that supplies sensation to the medial aspect of the forearm.
Medial Antebrachial Cutaneous Nerve
Nerve that supplies sensation to the arm just distal to the axilla
-A small area
-Anastomosis with the Median Brachial Cutaneous Nerve
-Emerges from the 2nd ICS, joins up with the Medial Brachial Cutaneous Nerve to form a nerve complex distal to the axilla
-Sensory ONLY
-Has to be blocked separately - does not arise from the Brachial Plexus
Intercostobrachial Cutaneous Nerve (T2)
